Chef John's Salad Lyonnaise

Remove and discard the root ends from each head of frisee lettuce. Chop leaves into 1-inch pieces and transfer to a large salad spinner. Fill with cold water, swish well to remove any dirt and sand, then drain and spin until completely dry. Keep in the refrigerator until ready to use.

Whisk shallots, Dijon, salt, pepper, and sherry vinegar together in a large bowl until well combined. Add oil slowly, a little at a time, and continue whisking until dressing is thick and emulsified; set aside.

Place bacon in a cold pan over medium heat; cook until crisp, 8 to 10 minutes.